TONY JONES, PRESENTER: The British Supreme Court has ruled the WikiLeaks founder Julian Assange should be extradited to Sweden.

He's wanted for questioning by prosecutors there over allegations of sexual assault.

Mr Assange's lawyers haven't given up hope the Supreme Court will re-open his extradition case on a technicality.

But his best, although still slim, hope of avoiding extradition lies with an appeal to the European Court of Human Rights.

Europe correspondent Philip Williams reports from London.

PHILIP WILLIAMS, REPORTER: This was seen as the last chance. Outside the court Julian Assange's supporters had gathered, so too the world's media. The only person missing was Julian Assange himself. He wouldn't have heard good news anyway.

NICHOLAS PHILLIPS, SUPREME COURT PRESIDENT: The majority has concluded that the Swedish public prosecutor was a judicial authority within the meaning of both the framework decision and the Extradition Act.

It follows that the request for Mr Assange's extradition has been lawfully made and his appeal against extradition is accordingly dismissed.

DINAH ROSE, ASSANGE LAWYER: We are therefore currently considering our position and whether or not it will be necessary, with great regret, to make an application to this court that this matter should be reopened so that we have an opportunity to argue this point.

I say this only to flag it up, because obviously at the moment we need to study the judgements and consult with our client.

PHILIP WILLIAMS: The court then granted Julian Assange's legal team two weeks to consider the ruling. That means it's just possible the case could be reheard if cracks in the split decision can be found.

GEOFFREY ROBERTSON, HUMAN RIGHTS LAWYER: It doesn't surprise me. I formulated this argument 18 months ago and said that the idea that a prosecutor was a judicial authority is a contradiction in terms. And so it is in Australian law, so it is in British law. But in European law, many of the European systems merge the judge and prosecutor. They don't make our distinction.

PHILIP WILLIAMS: There is one more legal avenue available beyond Britain; the European Court of Human Rights may be asked to take on the case, although that too may have limited prospects of success.

GRAB ROBERTSON: There are technical possibilities and of course - but the main issue is the European Court of Human Rights because that is the final court in Europe.

PHILIP WILLIAMS: The greater fear for Julian Assange is that once in Sweden the US government will find it easier to extradite him over his WikiLeaks activities. Outside the courtroom today his supporters were adamant the Australian Government was failing in its responsibilities to a citizen in trouble.

JOHN PILGER, ASSANGE SUPPORTER: They've made a special case of Julian Assange because he's the editor of WikiLeaks, because WikiLeaks has embarrassed the Australian Government, a lot of the WikiLeaks cables showed how Gillard got into power and mentioned her powerbrokers and their relationship with the US embassy in Canberra.

That's what Australians should be considering about this. It's an absolute disgrace.

PHILIP WILLIAMS: For the moment, Julian Assange continues his precarious life on bail with an electronic tag required to report regularly to the police and now waiting to see what if there's anything more his lawyers can do to keep him in Britain.

There is no certainty about what happens next, but if all avenues of appeal now fail, then he could find himself on a plane to Sweden in about a month's time, and a new chapter in this long-running saga will open. No-one knows where it'll finish.